The regulation change to 800cc displacement automatically led to a drop in power. Lack of power was constantly an issue for us and, as in years past, we placed top priority on power development characteristics in our development efforts. The second priority was maximizing cornering speed and stability. This was particularly important because of the reduced engine power. More sophisticated EMS control functions became the key. Feeding the engine more fuel would have been another option, but the new FIM regulation reduced fuel tank capacity from 22 to 21 liters that season. This resulted in even less power than initially expected. Nonetheless, our competitors came out with very powerful machines that left us far behind in the opening round at Qatar. This year's spec ended up being one that provided us with more issues than results.

Learning from the failures of the 2007 season, dramatic progress was made with the 2008 spec. It that sense, it can be likened to the 2004 model. To improve power performance within the 21-liter fuel restriction, we focused on reducing power loss. From this year's engine a pneumatic valve system was adopted. This succeeded in boosting top-end revs and reducing power loss at the same time. Changes were also made in the crankshaft lubrication system to further reduce power loss. The sum total of these changes made the 2008 model M1 a very good machine.
Furthermore, as Valentino has explained, the switch to Bridgestone tires led to major revisions in the machine geometrics. As we mentioned earlier, the wheelbase on the 2003 machine was very short, and that was true again with the 2008 spec. The introduction of the crossplane crankshaft had already improved rear-wheel traction and lightened tire wear. Now, in order to improve traction even more, we moved the machine's center of gravity further to the rear. This was achieved by shortening the rear arm. Although this reduced weight distribution on the front wheel, the performance of the Bridgestone front tire used this year was so good that it provided better front tire performance than in 2003 despite that load reduction. All of this made the 2008 machine the best Yamaha had fielded in recent years.

2009 model | 800cc YZR-M1
Big progress made in EMS

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This was again a year that saw major advances in EMS sophistication. Building on the progress made since 2006, this brought the EMS control functions to a nearly ideal state. The control system had reached the point where it functioned as a "smart brain" that enabled smooth and constant communication with the rider. Input from the many sensors positioned in vital parts of the machine enables simulations that are processed in real time by the machine's CPU and compared dynamically against data gained from the constantly changing running conditions, on wet and dry tracks and in hot and cold temperatures. This sophisticated control function made the 2009 model a highly competitive racer.